The present invention relates to an arrangement for regulating a supply flow and for limiting a supply pressure of an adjustable pump.
Arrangements of the above-mentioned general type are known in the art. In a known arrangement, a pressure differential acting upon a flow regulating valve is brought about by two throttling elements connected in series. One of the throttling elements is arranged in a supply conduit, whereas the other throttling element is arranged in a branching off conduit. Such a construction has a disadvantage in the fact that when a small excess of the pressure in the system or an untightness of a servo valve take place, a flow starts to travel through the throttling element arranged in the branching off conduit. Thereby the pump is set back exactly to such extent that the pressure drop at this throttling element is compensated by a small pressure drop at the throttling element in the supply conduit. This causes a transition region of pressure through which the supply flow slowly decreases. Thereby, the decrease of the supply flow can extend through a substantially greater pressure region than it is desired. In this case when the working pressure reaches its maximum value, strong deviations of the supply flow value take place.